This graphic shows why it is so impossible to get gun reform through Congress

The mass shooting in Orlando, Florida, was the deadliest mass shooting in modern American history. But the chances that Congress will pass meaningful gun control reform as a result are highly unlikely.

The Senate is highly polarized around gun policy: The National Rifle Association gives 56 senators an A grade — and 36 senators an F. That leaves 11 senators somewhere in between, with scores ranging anywhere from a B+ to a D-.

This makes it really tough to see any proposed gun control reform legislation moving through the Senate. A simple majority for a bill to pass requires only 51 votes, and, as we can see in the chart above, there are already 56 senators that are unlikely to vote for comprehensive gun control reform. And this, of course, is assuming that the proposed legislation makes it past the House in the first place.

I wasn’t able to access the NRA’s report card ratings for House members, as the NRA does not make its rankings publicly available (even to a member of the media who requested the information repeatedly). The only way to gain access to the NRA’s ratings is to become a paying member, so I relied heavily on 2012 work by the Washington Post and press releases from the NRA to fill in the gaps.

But if you look at the New York Times’s analysis of the 113th Congress in 2012, you’ll note the divide between pro-gun lawmakers and anti-gun lawmakers is similarly divided.

Of the 435 members of the House, the Times reported that 242 legislators received a score of A- or higher and 146 received a score of a D or F. Only 47 had a score in the middle or no score reported at all.

In 2012, the Pew Research Center found that public support for gun control doesn’t appear to be impacted by high-profile shooting incidents like what happened in Orlando.

Polling people immediately after the mass shooting at a movie theater in Aurora, Colorado, in July 2012, that killed 12 and injured 70 others, Pew found no significant change in public opinion on the issue of gun control and gun rights.

In fact, growing evidence suggests that immediately following a mass shooting is not the time to discuss increased gun control measures, period. There’s little compromise, and opposing political parties often stick to their lines of rhetoric — Republicans call for “thoughts and prayers” while Democrats call for gun control. But it does invite the question: If not now, when will we address the issue of gun violence as a nation?